Plug extractor



1931- F. JOHNSTON 1,818,626

I PLUG EXTRACTOR Filed Aug. 15, 1929 Inve mo 1 Leroy F. Johns tor},

Attorney.

Patented Aug. 11, 1931 UNITED STATES PATENT OFFICE LEROY F. JOHNSTON, OFNEW YORK, N. Y., ASSIGNOR TO WATERBURY CABLE SERVICE, INC., OF NEW YORK,N. Y., A CORPORATION OF NEW YORK PLUG Ex'rRAcroa' Application filedAugust 15, 1929. Serial No. 386,211.

The object of this invention is to provide an effective means forremoving tapering plugs which are used to seal openings in chambers, asfor example the chambers g formed around the splices for-lead coveredelectrical conductors as set forth inan application for plugs executedconcurrently .with this application. I

In the accompanying sheet the drawing which forms a part of thisdescription, the i figure is a section through an opening to a chamberwith a plug extractoraccording to tliis invention in place forwithdrawing the ug. 51 The chamber has sealed in its wall a metallicnipple 11 which forms an opening to the chamber. The nipple has anexteriorly threaded end 12, and the interior of the nipple has a smoothtapering seat for a go smooth tapering plug 13. The taper of the seatand of the plug is preferably close to two and one-half degrees with theaxis, as this has been found to be an angle at which the plug will notbe driven out by 5' such fluid pressures as it will ordinarily besubjected to when applied at the inner and smaller end, but which willrelease when pulled from the larger end. At the larger end of the plugis a threaded part 14 conveniently formed by a drilled and threaded'hole, but this kind of a thread is not essential. The thread because ofits smaller diameter is ordinarily of finer pitch than the thread on thenipple. A part 15 engages this thread, and in the form shown this is abolt which passes through a cap 16 on which the head of the bolt bears,and the cap engages the threaded end of the nipple. The cap has ahexagon top for engagement by a wrench.

To extract the plug, the cap is first screwed in place. Ordinarily theplug will be cov ered by a cap which has no hole in it, and this isfirst replaced by a cap having a hole for the bolt. The bolt is next setin place. Usually the plug holds so firmly that it is not practicable todislodge it by force di-.

rectly applied to turning the bolt since enough force may be required totwist the bolt apart. The removal is therefore efi'ected by means of awrench applied to thecap and as the unscrewing of the cap from thenipple is started the bolt is held from turning by holding the lever 17which passes through its head until after the plug has loosened itshold, so that slippage will be between the underside of the bolthead andthe cap and not between the bolt threads means for restraining theconnecting means.

from turning, and means for unscrewing the cap to withdraw the plugwhile the connectting means is restrained from turning.

'2. A plug extractor for a smooth tapered metallic plug with a threadedhole at its large end when seated in a metallic nipple with a threadedend, the extractor comprising a cap for engaging the threaded end of thenipple, a'bolt witha shank for engagement with the threaded hole in theplug and a head'for'seating on the top of the cap, means for restrainingthe bolt from turning, and means for unscrewing the cap to with draw theplug while the bolt is restrained from turning.

' LEROY F. JOHNSTON.

